The present invention relates to a penpoint tip that is particularly designed for use to draw a thick line with one stroke of a pen, or occasionally parallel thinner lines also with one stroke.
The penpoint tip of the present invention is intended for incorporation into an applicator that may be used to write characters, to draw thick lines, to color some figures or the like and/or to paint out some previously written incorrect characters or the like to be amended.
Ball-point pens are now widely used as a convenient ink applicator easy to use. However, the penpoint tips of the ball-point pens literally comprise each a xe2x80x98ballxe2x80x99 serving as a principal part for application of ink to any desired surfaces or articles. Such a ball will usually be brought into an extremely narrow xe2x80x98pointxe2x80x99 contact with those surfaces. Therefore, any thick line can neither be drawn with one stroke of the pen, nor any broad areas can be painted using such a ball-point pen.
Some prior proposals are disclosed for example in the Japanese Utility Model Laying-Open Gazette Sho. 58-69479, Patent Laying-Open Gazette Hei. 7-290877 and ibid. Hei. 7-290878. These proposals are directed to certain improved penpoint tips and applicators each employing a single roller in place of the ball and capable of drawing thicker lines.
Those prior art applicators comprise ink reservoirs and penpoint tips secured to the distal ends of the respective reservoirs, wherein each tip has only a single roller held therein. In use, this roller will be pressed to and rotated on a paper sheet or the like so that the roller covered and wetted with ink does continuously transfer it to the sheet, when drawing a thick line thereon.
In order to maintain tight and stable contact of the paper sheet with the ink applying roller in such a known penpoint tip, the applicator has to be kept at a proper angle relative to the sheet. Further, every stroke must be made perpendicular to the axis of said roller, rendering it somewhat inconvenient to use those known applicators. In addition, it has been considerably difficult for those penpoint tips to draw curved lines, even if straight lines could be drawn relatively easily.
Even if requirement for the roller to rotate at an even speed over its full width relative to the paper surface could be met when stroking straight lines, but it would not be met when drawing curved line. In the latter case, an inner and out edge regions of the roller cannot rotate simultaneously at the same angular speed. Such a roller almost incapable of turning smoothly have thus caused the curved lines to become broken and/or blurred.
As a result, the known roller-type penpoint tip have failed heretofore to write xe2x80x98unsimplexe2x80x99 characters or draw figures, even if possible to draw xe2x80x98simplexe2x80x99 straight lines.
Objects of the present invention made in view of such drawbacks inherent in the prior art is therefore to develop and provide a novel penpoint tip as well as a novel applicator having the tip incorporated therein, that are able to draw a thicker line, whether the line is straight or curved, and whether the line is transverse or oblique in any direction.
In order to achieve one of these objects, the penpoint tip proposed herein does comprise: a tip body, a plurality of balls, the tip body consisting of a ball retainer with an opening and an ink-feeding rigid tube formed integral with the ball retainer and having an ink feed bore in fluid communication therewith, wherein the balls are held in the ball retainer such that a part of each ball is exposed from the opening so as to be capable of applying ink onto an article surface, characterized in that the balls are held in the single and common ball retainer and arranged in a row in such a fashion that each ball has a part exposed outside.
The penpoint tip of the invention employs a plurality of balls incorporated therein instead of the prior art roller so that ink will be applied as the balls rotate.
In the present penpoint tip, each of those balls in a row is exposed in part from a ball retainer. With this tip pressed onto a paper sheet, all the balls in the tip will contact the sheet while rotating independently of each other. They will rotate at different rotational speeds while drawing a curved line. Some balls advancing along a smaller-radius edge of said line will rotate at speeds lower than the others advancing along a larger-radius edge will do. Ink will be applied to the sheet from all the balls and at substantially the same flow rate, thus enabling the tip to draw a thick or heavy line.
In a preferable embodiment or modification of the penpoint tip just described above, the opening formed in the ball retainer is of an elliptic contour or an elongated circular contour. The minor axis or shorter inner diameter of such an elongated opening is designed appropriately smaller than the diameter of each ball, thereby protecting the balls from unintended disengagement from the tip.
In this embodiment, the penpoint tip having the elongated opening whose minor axis is smaller than the balls will surely hold them in place not to slip off.
The elongated opening which the penpoint tip of the invention may preferably have a major axis that is equal to or less than the product of xe2x80x9cball diameterxe2x80x9d and xe2x80x9cthe number of ballsxe2x80x9d held in the retainer.
The penpoint tip having this feature is advantageous in that the balls are stabilized in position in the direction of major axis. The balls are thus protected from staggering perpendicularly or longitudinally of said major axis, whereby any unevenness or irregularity, in particular uneven width, will not be produced in lines drawn with the tip.
In another embodiment, a seat may preferably be formed in the ball retainer at its region that is located adjacent to the distal end of the ink feed bore. The balls in this case will rest on the seat that extends along the row of said balls.
The seat contacting and supporting the balls in this embodiment will render them stable in position, allowing smooth rotation.
In still another embodiment, the seat may desirably consist of a tapered and inclined flat plane.
The tapered flat seat in such an embodiment is devoid of arrow-shaped grooves (viz., xe2x80x98ink groovesxe2x80x99), so that the balls held stable on said seat can spin further smoothly.
In a further embodiment, recesses each being a part of a spherical surface are formed in the seat.
Ink application will be done with the balls resting on the seat and engaging with those spherical recesses. The balls in penpoint tip of this embodiment will take more stable positions without any mutual interference and will thus rotate more smoothly, also preventing any unevenness or irregularity, in particular uneven width, from being produced in the lines drawn with this tip.
In still further embodiment, groove-shaped cutouts are provided in the seat at positions thereof corresponding to the center of balls. Each ball does not abut against the bottom of each cutout, but does contact opposed edges thereof.
The balls in penpoint tip of this embodiment will likewise take very stable positions without any mutual interference and will thus rotate very smoothly, also preventing any unevenness or irregularity, in particular uneven width, from being produced in the lines drawn with this tip.
In an alternative embodiment, grooves are formed in the seat so as to communicate with the ink feed bore.
These grooves in this alternative embodiment will be advantageous in that ink supplied through the grooves and passing by the balls will completely wet them.
In a still further embodiment, the opening of the tip body is caulked along the balls.
The penpoint tip having such a caulked opening will more surely hold the balls in place, without hindering them from smoothly rotating.
In a different embodiment, the end opening of the tip body is corrugated.
Also in this embodiment, the balls will be retained in a reliable fashion ensuring smooth rotation thereof.
An applicator, particularly an ink applicator, also provided herein does comprises an ink reservoir and characteristically has fixed on its distal end such a penpoint tips as discussed in any of the preceding embodiments.
The penpoint tip in the applicator may either be attached directly to the reservoir, or more usually a connector may intervene between them.
The penpoint tip consulting the applicator will thus have a plurality of balls rotatable to apply ink to an article surface.
Also in the applicator of this type, the balls held in its penpoint will rotate independently of each other such that rotational speed is allowed to differ between the balls drawing a curved line. In detail, some balls advancing on or along a smaller-radius edge of said line will rotate relative to the paper sheet or the like slower than the others advancing on or along a larger-radius one. Ink will be applied to the sheet in this manner from all the balls, enabling the penpoint tip of the invention to draw a thick or heavy line.
In an embodiment of the applicator, it comprises a cylindrical shaft, and a distal end portion of the penpoint tip is slanted relative to this shaft.
The applicator of this type makes it possible to easily apply an ink to any article surface, keeping a convenient angle between the surface and the shaft.